Air compressing apparatus



Nov. 8, 1938.

L. H. BROWNE 2,136,098

AIR COMPRESSING APPARATUS 15 Sheets-Sheet 1 Filed July 28, 1957 INVENTORL z'ndsay H Browne.

ATTORNEYS Nov. 8 31938,

L. H. BROWNE AIR COMPRESSING APPARATUS Filed. July 28, 1957 5 ma ma 5Sheets-Sheet 2 'INVENTQR Y Llkwisa fi fmsgma.

Nov. 8, 1938. I. BROWNE AIR COMPRESSING APPARATUS Filed July 28, 1937 3Sheets-Sheet 3 m N m U A INVENTOR Lindsayliflrowne.

Patented Nov. 8, 1938 2,136,098 AIR COMPRESSING APPARATUS Lindsay H.Browne, Pittsiord, Y., assignor to Kellogg Compressor and ManufacturingCorporation, a corporation of New York Application July 28, 1937, SerialNo. 156,075

'1' Claims. (Cl. 230-58) This invention relates to improvements in airFigure 16 is a detail view of the valve plate;

UNITED STATES PATENT, OFFICE compressing apparatus. and

An object of the invention is to provide an Figure 17 isaverticalfragmental sectional view improved air compression unit including comofthe first stage suction and discharge valve pressor, motor, storage tankand accessories. structures and mounting taken on the line i1-l1, 5

Another object is to provide a unit of the Figure 12. above nature whichis quiet and smooth and Referring to Figure 1, the numeral 20indiefficient in operation. cates a storage tank provided with feet 2|and A further object is to provide a unit of the pressure gage 22.Brackets 23 welded to the tank above type in which the motor andcompressor 20 have secured thereto resilient mounting pads 10 aresupported on the tank by vibration absorbing 24, preferably of thestructure shown in detail means eliminating all metallic connectionsbein Fi ures 3 and 4- tween the elements. Referring to the latterfigures, the pad 24 Still another purpose is to provide improvedconsists of a cupped metallic mounting plate 25,

discharge means for delivering the compressed a rubber body 26 securedinto and extending 15 air into the storage tank by which noise due toabove the plate 25, and a central bolting cup 21 drumming or pulsationof the discharge is elimiof metal secured in the body 26 and resilientlynated, and by which any leakage from the valve separated thereby fromthe mounting plate. The outside the tank is rendered impossible. plate25 and cup 21 are preferably made of Another purpose is the provision ofa unit instampings provided with tongues 28 and 29 em 20 cluding acompound compressor having improved bedded in the rubber body 26, theentire assembly head and valve structure, and in which the beingpermanently Vulcanized together- The crankcase is sealed from the outerair. mounting plate has lugs 30 provided with A still further object isto provide improved holes 3| through which t e D is bolted to the 25means to cool the air between stages and before brackets 23, Figure 1,and'central holes 32 in 25 delivery to the storage tank. g the boltingcups 21 accommodate bolts 33, Figure Other objects and advantages of theinvention 1, by means of which a frame or base 34 is secured will becomeevident during the course of the folto the pads.

lowing description in connection with the ac- From the foregoin it W bee at t e 30 companying drawings, in whichbase 34 and tank 20, whilefirmly connected, are 30 Figure 1 is a perspective view of a preferredresiliently insulated from each other by the form of the invention; pads24.

Figure 2 is an exterior detail view of the u d on t s 3 is a mp ss 35.resilient discharge connecting device; preferably of the oe pe, nd aSuitable 35 Figure 3 is a plan view of a preferred form driving motor36. The compressor 35 has atriple 35 of resilient mounting device;grooved flywheel 31 acting as a pulley and driven Figure 4 is a verticalsectional view of the, throu h thr s 8 from th motor pu l y same; 39.The spokes 40 of the flywheel 31 are formed Figure 5 is a longitudinalsectional view of one s fen-vanes, Which When in motion p v de a 40 formof the discharge check valve; blast of cooling air as hereinafter setforth. 40

Figure 6 is an end elevation of the same; T Compressor 35 is q pp d w ha ead Figure 7 is a side elevation of the same; Ofa yp Shown in detailin Figures 13 nd. Figure 8 is a longitudinal sectional view of an thehead being belted t0 the cylinder ock alternative form of dischargecheck valve; Figure The block 42 has e low Pressure 01 rst 5 Figure 9 isan end elevation of the ame; stage cylinder 43 and a high pressurecylinder Figure 10 is a detail view of the discharge check the lines 011Which the inner u e ences valve disc shown in Figure 8; of thesecylinders register with the headv 4i Figure 11 is a detail view of thespring tai r being indicated by dotted and dashed lines 45 and for thesame; 46 respectively on the bottom view of the head, 50 Figure 12 is ahorizontal sectional view of the Figure 50 cylinder head; A suction orinlet elbow 41, Figures 12 and 13, Figure 13 is a bottom view of thesame; preferably integral with the head 4|, leads into Figure 14 is adetail view of the valve seat ring; an inlet pocket 48. Two valves 49and 50, con- Figure 15 is a similar view of the valve restructed in amanner hereinafter described, pertainer ring; mit the passage of airfrom the pocket 48 to the 55 first stage cylinder 4i. A second pair ofvalves 5| and 52 permit discharge of air from the cylinder 4| to asecond pocket 53, from which a connector elbow 54, Figures 1 and 12,conducts the air to a finned tube 55. The tube 55 is formed in a loopdisposed in position to receive a blast of cooling air from thefan-blade spokes 40 0f the flywheel 31, and leads through a second elbowfitting 56, Figure 12, into the inlet pocket 51 of the second or highpressure stage of the compressor. The finned tube 55, so disposed as toreceive the cooling blast from the flywheel, this operates as aninter-cooler between stages of the compressor to dissipate heat ofcompression from the first stage.

From the pocket 51 a valve 58, of construction identical with that ofvalves 49 and 50, admits the air to the high pressure cylinder 44 fromwhich after compression it is discharged through a valve 59 and pocket68 to a discharge tube 6| hereinafter described.

All the valves noted above are of identical construction, consisting ofparts shown in detail in Figures 14, 15, 16 and 17. These parts consistof a seat-ring 62, a guide cup 63, a valve plate 64 and a conicalcompression spring 65.

The seat-ring 62 has a flat annular seat portion 66 raised slightlyabove the outer rim of the ring and above a central depression 61, theseat portion 66 being pierced by a plurality of arcuate slots 68.

The guide cup 63 consists of a short cylindrical barrel 69 formedintegrally with a flat perforated head or spider I0. Both the seat ring62 and guide cup 63 are threaded on their peripheries.

The valve plate 64 is of thin resilient steel, and is hexagonal in shapein rounded corners H and a central hole 12.

Figure 17 shows in sectional detail the manner in which two identicalsets of the above parts are disposed in the head 4| to form inlet valveassembly 49 and discharge valve assembly 5|.

Referring first to the inlet valve assembly 5|, Figure 17, it will beseen that the seat ring is screwed against a shoulder 18 at the upperend of a threaded hole 14 leading from the lower face of the head 4| tothe pocket 48, the annular seat portion 66 being directed downwardly.The thin valve plate 64 is held against the seat 66 by the conicalspring 65, covering the arcuate slots 68. The guide cup 68 is screwedinto the threaded hole 14, the end of the cylindrical barrel 68 tightlyengaging the rim of the seat-ring 62 and locking both parts in place.The rounded corners of the valve plate 64 fit loosely inside the barrel6! which thus serves to guide the valve plate, the spider 10 serving toholdthe spring 65 in compression against the valve plate to urge thelatter against its seat 66.

The end of the barrel 68 is bevelled at 15 and the shoulder 18 may begrooved or undercut at I6, thereby providing narrow circles of contactbetween the mating parts and permitting air-tight joints without the useof gaskets.

When by descent of the piston in the compressor cylinder 43 a partialvacuum is created therein below the head 4|, the preponderance ofpressure in the inlet pocket 48 acts through the arcuate slots 68 topress the valve plate 64 downward from its seat 66 allowing air to passthrough the spider 10 and into the cylinder. In its passage the airpasses around the hexagonal periphery of the valve plate and alsothrough the central hole 12, giving a relatively large area of inletopening with very small motion of the valve plate. This fact,

together with the extreme lightness and resilience of the valve plate,results in very quiet valve action and low resistance to the passage ofair, which advantages are further augmented by the use of the twoidentical inlet valve assemblies 48 and 50 to divide the total volumedrawn into the compressor.

The discharge valve assembly 5| is identical with the inlet valveassembly 49 described above except that the entire assembly is inverted,the head or spider end of the cup 63 being screwed against the shoulder13 and the seat ring 62 becoming the locking member. The operation ofthe valve is the same as described except, of course,

that it permits discharge of air from the first stage cylinder 43 to theinlet pocket 51 of the high pressure cylinder.

The inlet and outlet valves 58 and 59 of the second or high pressurestage are identical in structure with those described. Thus all valvesare interchangeable, a condition highly advantageous both from theview-points of manufacture and service. The simple and compactstandardized valve structure allows great flexibility in design of thecompressor for different sizes and capacities, as the valves may bedisposed singly or in multiple in any desired combination. To widen thefield of capacities for which the compressors are designed, a secondstandardized valve assembly may be provided, identical in structure withthat described above, but of smaller size, and in some cases assembliesof both sizes may be embodied in one compressor in order to achieve themost advantageous spacing, grouping and capacity of valves.

The discharge tube 6|, previously referred to, is composed of externallyflnned tubing. It is formed in a loop encircling the shaft of thecompressor in the zone of air blast from the flywheel fan spokes 40 asshown in Figure 1. The tube 6| thus constitutes an after-cooler givingup heat of compression to the flywheel air-blast in the same manner thatthe loop 55 operates as an intercooler.

The discharge tube 6| terminates in a union 11 to which is secured alength of resilient hose or tube 18, Figures 1 and 2, preferably of areinforced synthetic rubber construction. The

. other end of the resilient section 18 is secured to a threadedconnector 18 which is screwed tightly into the inlet end 80 of a checkvalve assembly 8| shown in detail in Figures 8, 9, 10 and 11.

Referring to Figure 8, it will be seen that the check valve unit 8| hasa body 82 into which is threaded a cap 83 formed with a constrictedcentral 'nozzle 84 and enclosing a cylindrical chamber 85. A resilientseat ring 86, of rubber or the like, is fitted into an annular recess inthe body 82, a thin cylindrical inner wall 8'! of the latter extendingsubstantially through the rubber ring so that the latter is rigidlysupported against distortion,

on its inside as well as on its outside circumference. A valve disc 88has a raised annular portion 88 engaging the seat ring midway betweenstop to limit the opening motion of the valve disc 88.

The body 82 is provided withan exterior tapered thread 85 which isscrewed into a suitable fitting 86 in the top of the tank 20, Figure 1.Thus, the entire valve mechanism projects inside the tank 20, and thereare no exterior joints in the check valve assembly through which leakagemight occur to the outer air.

In operation, the chamber 85 and restricted nozzle 84, both locatedinside the tank 20, act as a a muffler for discharge of compressed airinto the tank. Any pulsations of air through the valve are equalized inthe chamber 50 so that the discharge of the air through the nozzle 84occurs smoothly and at a practically constant rate. By this meansdrumming or audible vibration of the air discharge into the tank iseliminated. The motion of the. valve disc 88 takes place entirelybetween resilient limiting means, that is, between the rubber seat ring86 and the stop spring 95, so that no clicking or hammering can arise atthis point. The combination of this valve action and the elimination ofpressure pulsations as described above results in a substantially silentair discharge into the tank 20.

The contact of the valve disc with the middle portion of the face of therubber seat 86, and the latters rigid support, as previously set forth,resulting in long seat life and sustained tightness of the valve.

A tapped hole 81 in the valve body 82 near its inlet end is provided topermit connection by means of a small flexible tube 98, Figure 1, to acombined pressure switch and magnetic unloader 89 mounted on the base 34behind the motor 36. The structures of such pressure switches andunloaders are well known to those skilled in the art and therefore arenot described herein, their functions being to break the motor circuitwhen the pressure in the discharge line rises to a predetermined pointand at the same time to exhaust the discharge line to the atmospherethrough the tube 98, so that restarting of g the compressor occurs onlyagainst atmospheric pressure.

With small compressors an alternative form of check valve unit shown inFigures 5 and 6 may be used, in which the body I00 is constructed at IOIfor a tubing union connection. The cap I02 encloses the equalizingchamber I03 in which is guided a light disc valve I04 and itscompression spring I05. The cap I02 has an exterior annular steppedgroove I00 from which a hole I01 leads into the chamber I05. A resilientmetal clip I08 is sprung into the outer step of the groove I06, leavinga slotted opening I08 disposed circumferentially opposite to the holeI01.

In operation, the alternative valve unit functions .in substantially thesame manner as pre-- Some of the air from the viously described.equalizing chamber I03 escapes directly through a small hole IIO, butthe major portion is forced to pass out the hole I01, thence around theannular passage formed by the groove I05, and finally out at the slotI08. By the restriction and labyrinthine passage of the air from chamberI03, pulsations and drumming are eliminated as previously set forth.

The crank case III of the compressor 35, Figure 1, is not provided withthe usual atmospheric breather, but instead a pipe II2 leads from thecrank case to a tapped boss H3 in the inlet elbow 41. A combined inletmuiller and air filter II4, secured to the end of elbow 41, silences andfilters all inlet air drawn into the compressor. The connection of thepipe II2 as described allows the crank case to be sealed from the outerair, all breathing taking place with filtered air from the muiiied inletpassage. Contamination of the crank case lubricant with dust and dirt isthereby avoided, and the panting sound common to open breathers isentirely eliminated.

From the foregoing description it will be seen that the cooperation ofthe features of the invention set forth throughout cooperate to producea silent and eflicient compressing unit.

Pneumatic noises are eliminated by the inlet muflier, internal breather,light and efficient compressor valves, and the combined check valve anddischarge muffler structure, while the resilient connection of thecompressing mechanism to the tank 20 by means of the pads 24 and theflexible discharge coupling 18 prevents transmission of any mechanicalor electrical vibrations to the tank and its foundation.

The location of the finned inter-cooler 55 and after-cooler 6| in theair-blast of the flywheel 31 contribute to the quietness of the machineby eliminating auxiliary fans, and the shape and large cooling surfaceof these members exposed to the air blast, in cooperation with extensivecooling fins II5 on the cylinder head 4I, provide thorough dissipationof the heat of compression prior to delivery of air to the storage tank20.

While the invention has been described in preferred form, it is notlimited to the precise structures set forth, as various modificationsmay be made without departing from the scope of the appended claims.

What is claimed is: I

1. In an air compression device, in combination, a storage tank, aplurality of resilient pads secured to said tank, a compressor basemounted on said pads and secured thereto, a compressor on said base, amotor on said base and connected to said compressor to drive the same, adischarge line on said compressor, a discharge check valve within saidtank, means including a resilient tubular coupling joining saiddischarge line to said check valve, and control means including means torelease the pressure from said discharge. line and resilient coupling.

2. The combination claimed in claim 1 wherein said control meansincludes means on said base and responsive to pneumatic pressure tocontrol the operation of said motor and compressor, and a resilient tubeadapted to transmit discharge pressure from the inlet side of said checkvalve to said control means.

3. In a device of the character described, in combination, a storagetank, a compressor resiliently mounted thereon, a discharge line on saidcompressor, a check valve in said storage tank, a resilient couplingconnecting said discharge line to said check valve, and resilientlyconnected means to unload pressure from said air compressor having a.discharge line and means to unload pressure from the same, a storagetank, and a check valve unit connected to said line and secured to saidtank in sealing relation, said unit comprising an elongated bodyprojecting into said tank, a check valve in said body within said tank,and means in said tank to retain said valve in said body.

6. In a device of the character described, a. discharge check valve unitcomprising a body having an inlet passage therethrough, a closure cap onsaid body and forming therewith an enlarged expansion chamber at theinner end of said passage, said cap having a constricted outlettherethrough, a resilient seat ring in said body surrounding the entryof said passage to said cham" ber, a valve disk guided in said chamber,and a spring urging said disk against said seat ring, said cap having acircumferential groove with stepped sides and a hole connecting saidgroove with said chamber, and including a snap ring disposed in theouter step of said circumferential groove, said snap ring having a slotspaced circumferentially from said hole whereby an exit from said cham-'her is provided through said hole, around the inner step of said grooveand through said slot.

'7. In an air compression device, in combination, a storage tank, aplurality of resilient pads secured to said tank, a compressor basemounted on said resilient pads, a compressor on said base, saidcompressor having an inlet pipe and a closed crank-case, means on saidinlet pipe to silence the intake of air thereto, a breather tubeconnecting said crank-case to said inlet pipe between said silencingmeans and said compressor, a discharge line on said compressor, a checkvalve in said tank, means including a resilient coupling connecting saiddischarge line to said check valve, means to silence the discharge ofair through said valve into said tank, and unloading means to releasethe pressure from said discharge line.

LINDSAY H. BROWNE.

